The Female Black Ops are enemies faced in Half-Life.

They are United States government martial-arts-trained commandos sent to clean up the Black Mesa incident by killing anything that moves. They have infamously large, cartoonishly jiggly breasts that are amazingly complimented by their black cat-suits that make them look like ninjas. Their faces are completely obscured by night-vision goggles and a balaclava, although once they die their goggles are lifted to reveal their eyes and show that they're quite tan.